1. Oct 17, 2013 #1

   qedigiv

   

   If we are looking further and further back in time when we look at more and more distant galaxies, then how do we know that they are accelerating (instead of that they were accelerating a long long time ago)??

    

   qedigiv, Oct 17, 2013
2. 
   Phys.org - latest science and technology news stories on Phys.org

   • • Astrophysicist predicts detached, eclipsing white dwarfs to merge into exotic star
   • • Can astronauts see stars from the space station?
   • • Evidence found of white dwarf remnant after supernova
3. Oct 17, 2013 #2

   mfb

   

   Insights Author

   2016 Award

   Staff: Mentor

   You can look at galaxies everywhere from "now" to ~13 billion years ago. This allows to get the current velocities as well as the velocities in the past.
   You don't see the same galaxies as they are now and as they were 13 billion years ago, of course, but if you see the current velocity of galaxies nearby you can extrapolate this to get the current velocity of more distant galaxies.

    

   mfb, Oct 17, 2013

• Log in with Facebook
• Log in with Twitter

Your name or email address:

Do you already have an account?

• No, create an account now.
• Yes, my password is:
• Forgot your password?

Stay logged in